During the last two decades different types of small electronic input devices have been developed, especially for mobile telecommunication. These devices generally have a keypad comprising either a set of buttons typically used on a telephone handset or a small keyboard in the QWERTY format.
It is common in such electronic input devices to provide a display to let a user see information which has been entered via the keypad or keyboard and to provide the user with other information such as received messages, instructions or other information. Developments in electronic and battery technologies have allowed manufacture of ever smaller devices having ever greater functionality. This improvement in functionality has enabled users to interact with electronic input devices in more ways, which has led to more menu options being available. Consequently, electronic input devices generally require a relatively large display and a large number of input keys. It is now common for users to carry their electronic input devices with them most of the time. This increased mobility generally limits the size of electronic input devices to a handheld size. Furthermore, since they are now often carried about, they need to be robust. There is thus a conflict between the need to have a large display and a large keyboard to allow ease of use and the need to have a small portable electronic input device.
In order to keep the size of electronic input devices small, it is known to provide browsing menus to display only a small number of available options and/or information at any one time and to reduce the size of keyboard keys. However, user interfaces of newer and more complicated devices, such as mobile telephones and Personal Digital Assistants, often have a computer-like functionality, and so require a display which is capable of displaying text (having a number of rows) and graphics. QWERTY format keyboards are often provided. An example of such a device is the Nokia® 9000 Communicator. This is in the form of a two-part mobile station comprising a complete QWERTY format keyboard in one part and a display having 640×200 pixels in the other part. The two parts are joined together by a hinge.